AGATHO, a Sicilian by birth, was remarkable for his charity and benevolence, a profound humility, and an engaging sweetness of temper. Having been several years treasurer of the church of Rome, he succeeded Domnus in the pontificate in 679. He presided by his three legates in the sixth general council and third of Constantinople, in 680, in the reign of the pious emperor Constantine Pogonatus, against the Monothelite heresy, which he confuted in a learned letter to that emperor, by the tradition of the apostolic church of Rome: acknowledged, says he, by the whole Catholic church, to be the mother and mistress of all other churches, and to derive her superior authority from St. Peter, the prince of the apostles, to whom Christ committed his whole flock, with a promise that his faith should never fail. This epistle was approved as a rule of faith by the same council, which declared, that Peter spoke by Agatho. This Pope restored St. Wilfrid to the see of York, and was a great benefactor to the Roman clergy and to the churches. Anastatius says, that the number of his miracles procured him the title of Thaumaturgus. He died in 682, having held the pontificate two years and a half. His feast is kept both by the Latins and Greeks. See Anastatius published by Bianchini, also Muratori and Labbè, Conc. T. 6. p. 1109.

The style of this popes letters is inferior to that both of his predecessors and successors. The reason he alleges in excusing the legates whom he sent to Constantinople for their want of eloquence, is because the graces of speech could not be cultivated amidst the incursions of Barbarians, whilst with much difficulty they earned their daily subsistence by manual labour; but we preserve, said he, with simplicity of heart, the faith, which our fathers have handed down to us. The bishops, his legates, say the same thing: Our countries are harassed by the fury of barbarous nations. We live in the midst of battles, inroads, and devastations: our lives pass in continual alarms and anxiety, and we subsist by the labour of our hands.